1. Field of the Invention
The present invention relates to heat exchangers. More specifically, the present invention relates to wound plate heat exchangers.
2. Description of the Prior Art
Plate-type heat exchangers, sometimes referred to as lamella heat exchangers are known. The principle behind such heat exchangers is that efficient heat transfer is obtained with the fluid to be cooled arranged in relatively thin layers which contact a large heat exchange surface area, such as one or more plates.
Depending upon the application, it is often difficult or impossible to provide the necessary volume within which a plate-type heat exchanger can be located. Accordingly, wound plate heat exchangers have also been developed wherein the plates are wound into a spiral or the like.
U.S. Pat. No. 1,110,065 to Linga shows a wound plate heat exchanger wherein a thin chamber is divided into two regions and is wound into a spiral. Working fluid enters one of the regions at the outer edge of the spiral and moves inwardly to the inner edge of the spiral. At the inner edge, the working fluid enters the other region and moves outwardly to the outer edge of the spiral where it exits the heat exchanger. A cooling fluid, such as air, passes between the convolutions of the spiral to cool the working fluid.
U.S. Pat. No. 731,469 to Le Pontois shows another spiral wound plate heat exchanger wherein a single-region spiral chamber is arranged at the center of a cast annular inlet manifold. Working fluid enters the outer edge of the spiral from the inlet manifold and exists the inner edge of the spiral through a pipe-like outlet manifold. Cooling air is drawn or forced between convolutions of the spiral by a suitable means.
However, problems exist with existing prior art wound plate heat exchangers in that, in many circumstances, additional means are required to draw or force cooling air through the convolutions of the exchanger. In uses such as cooling systems for motor vehicles, a separate fan and/or duct work must be provided to ensure an adequate supply of cooling air to the heat exchanger. Further, if such a wound plate heat exchanger is employed to cool the engine coolant of a motor vehicle, separate provision would have to be made to supply cooling air to other heat exchange devices which may be present, such as an air conditioning condenser, oil cooler, etc.